The invention relates to a lock, in particular a brake disk lock for motorcycles, comprising a lock housing and a bolt lockable thereto, with the bolt having a stop member, a bolt head and a bolt neck arranged therebetween, and with the lock housing having a receiving region to receive the bolt head of the bolt, a lock cylinder and a latch movable by a rotary actuation of the lock cylinder to lock or unlock the bolt head inserted into the receiving region.
To lock an object using such a lock, the bolt is guided with its bolt head pointing forwards through a passage aperture of the object, for example, through a venting aperture of a motorcycle brake disk, so that the stop member abuts one end of the passage aperture and the passage aperture grips around the bolt neck. The lock housing is then set onto the bolt head protruding from the other end of the passage aperture such that it projects into the receiving region of the lock housing. The latch is subsequently guided over the bolt head by means of a rotary actuation of the lock cylinder. The lock is secured against being removed from the passage aperture by the abutting of the stop member and the locked lock housing at respective ends of the passage aperture.
It is known to lock the bolt head inside the lock housing to provide a locking sleeve with a peripheral groove, which can be rotatably actuated by the lock cylinder, as the latch. The bolt head of the bolt can be inserted into or removed from the receiving region of the lock housing through a correspondingly wide section of the peripheral groove in the unlocked state of the lock. The locking sleeve is turned to lock the lock, with a narrower section of the peripheral groove being turned along the bolt neck over the bolt head of the bolt so that the bolt head is locked against removal from the lock housing.
The disadvantage with the known lock is that the accommodation of the locking sleeve rotating around the receiving region requires additional space in the environment of the receiving region. The design of the lock thus becomes larger in an unwanted manner in the environment of the receiving region.
It is an object of the invention to provide a lock whose locking mechanism requires the lowest possible volume, in particular in the environment of the receiving region provided for the bolt head of the bolt.
This object is satisfied for a lock of the kind initially mentioned by the lock housing further having at least one conversion element, by means of which a rotary actuation of the lock cylinder is convertible into an axial locking or unlocking movement of the latch.
With the lock in accordance with the invention, a conversion element therefore provides that a rotational movement of the lock cylinder actually effects an axial movement of the latch. In an unlocking movement, the latch is therefore removed from the receiving region in a lateral direction in a straight line and thus in the most direct way possible so that no free space has to be left free for a locking or unlocking movement of the latch or for a corresponding locking mechanism in the whole other environment of the receiving region. A cylindrical free space surrounding the receiving region, as is required in the prior art, can, in particular, be omitted. The axial movement of the latch effected by the conversion element thus leads to a substantial reduction in the space requirements of the locking mechanism in the environment of the receiving region of the lock housing.
As the action of the conversion element results in the latch only having to execute an axial movement, it can be made flat or only slightly curved at least in the environment of the receiving region of the lock housing, so that a further advantageous reduction in the depth of the lock housing is achieved.
The invention furthermore allows a new shape for the bolt head of the bolt. The bolt head has previously been spherical in shape, that is, designed with a round cross-section corresponding to the rotational movement of the locking sleeve. As only an axial locking or unlocking movement is provided in the invention, it is sufficient if the bolt head extends in a disk-shaped, flat manner with a round or angular outline within a plane which extends perpendicularly to the direction of the insertion of the bolt head into the lock housing or to the longitudinal direction of the bolt neck. Such a disk-shaped design of the bolt head leads to a further reduction in the lock housing depth and to the volume required for the receiving region.
The conversion element mentioned can be provided as or on a separate component that connects to both the lock cylinder and the latch. Alternatively or additionally, a conversion element can be integrated in the latch and/or the lock cylinder.
In a preferred embodiment of the invention, a conversion element provided inside the lock housing is made as an inclined guide which cooperates with a further conversion element, in particular a cam or a further inclined guide. This inclined guide or the further inclined guide can be made, for example, as a curved edge of a part of the lock housing, as an end of a section of a lock housing part extending with a curve or as a groove extending with a curve inside the lock housing which abuts in each case the cam or the further inclined guide respectively or engages with the cam or the further inclined guide respectively.
It is furthermore possible for two pairs comprising in each case an inclined guide and a cam cooperating therewith or an inclined guide cooperating therewith respectively, with one pair effecting the locking movement of the latch and the other pair the unlocking movement in response to a corresponding rotary actuation of the lock cylinder. As an alternative, a single pair of cooperating conversion elements can also be provided, for example for the unlocking movement of the latch. In this case, the respective counter axial direction of the lock can be effected by a restoring spring.
It is furthermore preferred when a driver is provided in the lock housing which is rotationally effectively connected to the lock cylinder and has one or more conversion elements. As a result of this, no special conversion elements have to be provided on the lock cylinder itself, which allows the use of commercial lock cylinders in an advantageous manner. Such a driver is, however, not absolutely necessary; for example, the cam of the lock cylinder can also cooperate with a conversion element, for example an inclined guide, provided on the latch.
In a particularly advantageous embodiment of the invention, at least one holding element is provided in the environment of the receiving region to hold the bolt head of the bolt inserted into the receiving region. When unlocking the bolt head inserted into the receiving element, such a holding element prevents the bolt from accidentally leaving the receiving region and falling out of the lock housing.
Such an uncontrolled release of the bolt from the lock housing can lead to damage to the locked object, for example to damage to a motorcycle rim surrounding a brake disk. Such an uncontrolled release of the bolt can, however, frequently not be easily avoided, as when the lock is being unlocked, the lock cylinder is rotatably actuated by one hand and the lock housing held against it by the other. This problem is solved by the holding element which only releases the bolt already unlocked, when the user deliberately pulls the unlocked bolt out of the lock housing or pulls the lock housing off the bolt.
Such a holding element cannot be provided easily for a lock in accordance with the prior art since - as explained - the locking sleeve serving as the latch surrounds the receiving region of the lock housing along its whole periphery and thus does not leave any space for an additional holding element.
The holding element preferably has at least one latch element at which the bolt head can be latched when inserted into the receiving region. This latch element can, for example, be formed by a closed ring-like holding edge or one or more pairs of latch arms opposing one another in each case which grip resiliently behind the bolt head. To fulfill the holding function described even when the bolt hangs down vertically, the holding force exerted by the holding element is preferably greater than the weight of the bolt.